When the current register was started on 22nd July 1919, the Paris International Conference allocated the prefix G- followed by four letters for British Empire registrations. Civilian aircraft flying on former military serials and those allocated with the K-100 series were initially re-registered sequentially from G-EAAA. G-EAAA to G-EBZZ, and G-EDCA were allocated to Heavier-than-air aircraft.